The Clinical Laboratory in a modern medical center is charged with the introduction and performance of many diagnostic tests. Automated data processing in the laboratory has led to an explosive increase in demands placed upon it and has forced the contemporary hospital laboratory to provide volumes of poorly used information. We aim to redirect the utilization and interpretation of diagnostic tests by the use of computer-assisted decision aids in laboratory medicine. We will select problems in laboratory testing that emphasize the patient care functions of clinical pathology, and will develop an integrated Laboratory Medicine Decision Analysis system that bridges the disciplines of clinical decision making and laboratory data analysis. Our methods will involve the development of computer-based mathematical models of prognosis and decision trees, to enable us to study new laboratory tests with respect to their potential clinical effects. We will apply the mathematical tools to screening protocols, therapeutic monitoring, and management of an entire component of the clinical laboratory. We will also develop computer-assisted educational programs to inform physicians and all health care personnel of the use of decision making methods in both clinical and laboratory-based problems. If quantitative techniques are to be accepted and applied routinely to medical management problems, we believe that education of medical personnel is of equal importance with primary investigation.